Myths vs evidence
Most curly content states everything with equal confidence. Some of it is real biology. Some of it is helpful technique that works but is not a law of nature. And some of it is folklore, repeated so often it started to sound true. The three get blended together and passed around as if they carried the same weight. They do not.
Here is the difference. We mark a claim as busted when the evidence clearly points the other way, and as contested when the honest answer is that nobody has settled it yet. Every entry has a source you can check.
Myths worth busting
These are the ones the evidence actually contradicts, not just claims we happen to dislike.
"Curly hair is inherently high maintenance."
Curly hair needs specific care, not necessarily more care. The daily struggle most people report usually comes from mismatched products and technique, not from the hair being difficult by nature. Once the routine fits the texture, the effort often drops. Evidence
Source: Only Curls, "Curly Hair Myth Busting: 10 Curl Myths Debunked" (onlycurls.com/blogs/news/curly-hair-myth-busting-10-curl-myths-debunked)"You either have curls or you don't."
Curl pattern can be suppressed and later recovered. Heat styling, chemical processing, dry brushing, and product buildup can flatten waves and curls for years, which is why so many people believe their hair is simply straight. Reducing those stressors often brings the pattern back. Evidence
Source: Only Curls, "How To Tell You Have Wavy or Curly Hair" (onlycurls.com/blogs/news/how-to-tell-you-have-wavy-or-curly-hair); OLAPLEX, "Bring Those Curls Back To Life" (olaplex.com/blogs/news/read-this-and-olaplex-those-curls-back-to-life)"Brushing is good for all hair."
This one is context dependent. Gentle brushing distributes scalp oil and removes shed hairs, which is genuinely useful on straighter hair. But brushing dry curly hair breaks the curl clumps apart and drives frizz and breakage. Textured hair should be detangled while wet, with conditioner in, using fingers or a wide-tooth comb. Evidence
Source: American Academy of Dermatology, "Tips for healthy curly hair" (aad.org/public/everyday-care/hair-scalp-care/hair/curly-hair-care)"You need to wash curly hair every day."
Over-washing strips the natural oils that curls depend on to stay soft and defined. Curly hair generally does better with less frequent washing and more conditioning. For very curly and coily hair, the American Academy of Dermatology suggests washing as infrequently as every two to three weeks. Evidence
Source: American Academy of Dermatology, "Tips for healthy curly hair" (aad.org/public/everyday-care/hair-scalp-care/hair/curly-hair-care)"More products mean better curls."
For beginners the opposite is usually true. Two or three consistent products used well beat a full cabinet, and buildup from layering too many products is one of the most common reasons the curl pattern disappears. Start small and add only when you can name what a product is for. Evidence
Source: CurlyNikki, "Curly Hair Routine for Beginners: The Ultimate Step-by-Step Guide" (curlynikki.com/curly-hair-routine-for-beginners-the-ultimate-step-by-step-guide-for-2025.html)"Curly hair grows more slowly."
This is a widely repeated belief, but the research describes it as a preconceived idea rather than a demonstrated fact. Curls can look like they grow slower because the coil takes up length, and because they are more prone to breakage that shortens retained length. That is not the same as the follicle producing hair at a slower rate. Evidence
Source: PMC, review on curly hair biology and care (pmc.ncbi.nlm.nih.gov/articles/PMC12094410/)Claims that are not settled
These get repeated as rules. They are better understood as open questions. Some may hold up. The honest position today is that the evidence is not there yet, so treat them as opinions, not facts.
"Avoid all sulfates."
How harsh a shampoo is depends on the whole formula, not one ingredient on the label. Sulfate-free versions often just clean less, which can suit dry curls but is not automatically better. An occasional clarifying wash with a stronger cleanser can help when buildup is the real problem.
Source: Lab Muffin Beauty Science, "The Science of Sulfate-Free Shampoo" (labmuffin.com/sulfate-free-shampoo-science/)"All silicones are bad."
Silicone is not one thing. Water-soluble silicones rinse out easily, non-soluble ones can build up without stronger cleansing, and volatile ones evaporate. Whether a given silicone helps or hurts depends on which type it is and how you wash. Blanket avoidance throws out the useful ones with the heavy ones.
Source: Curl Warehouse, "Are All Silicones Bad for Curly Hair?" (curlwarehouse.com/blogs/news/are-all-silicones-bad-for-curly-hair)The water-glass "float" porosity test.
Drop a strand in a glass of water and see if it sinks. In practice this mostly detects surface damage rather than true porosity, and it is thrown off by any product residue on the hair. It has never been scientifically validated. Treat whatever it tells you as a rough hint, not a diagnosis.
Source: Lab Muffin Beauty Science, "Hair Porosity Tests Are a Lie" (labmuffin.com/hair-porosity-tests-are-a-lie/)"Protein overload" and a strict "protein-moisture balance."
The idea can be a useful practical lens for noticing when hair feels stiff and brittle versus mushy and limp. But these specific terms do not appear in peer-reviewed literature, and the tidy balance model is more a community framework than an established mechanism. Use it as a language for symptoms, not as settled chemistry.
Source: CurlsBot, "Is Protein Bad for Low Porosity Hair?" (curlsbot.com/blog/is-protein-bad-for-low-porosity-hair)Curl-type numbers (2A to 4C) as a diagnosis.
The number system ignores density, porosity, and elasticity, which matter more for how hair actually behaves. Most heads are a mix of patterns rather than one clean type, and the original system could not even classify 4C hair. It works as shorthand for talking about shape. It does not work as gospel.
Source: PMC, review on hair classification systems (pmc.ncbi.nlm.nih.gov/articles/PMC13046883/)What is not in dispute
A short list of things the evidence does agree on, so the whole page is not caveats.
- Evidence Curly hair is anatomically drier and more breakage-prone than straight hair. The shape of the strand makes it harder for scalp oil to travel down the length.
- Evidence Gentle handling reduces damage. Detangle when wet, skip the rough towel, do not dry-brush, and touch the hair less while it dries.
- Evidence Tighter coils are drier and need more layered moisture and less frequent washing than looser waves. Coily hair is not "high effort for no reason," it simply has different needs.
None of this replaces figuring out what your own hair does. If you are still not sure what you are working with, the two-minute quiz gives you a starting point, and the plain-English ingredients page covers sulfates, silicones, and protein in more depth so you can read a label without the fear-mongering.
Educational, not medical advice. If you have scalp irritation, sudden shedding, or hair loss, please see a dermatologist or trichologist.